The present invention relates generally to two-wheeled vehicles. More particularly, the present invention relates to a rear suspension system for two-wheeled vehicles, such as motorcycles, employing pivoting arm assemblies and control arms possessing shock absorption characteristics and providing lateral stability.
The existing designs of most prior art rear suspension assemblies for two-wheeled vehicles include a rear axle pivot from a single point either from a dual or mono shock system that either extends or compresses the shock unit. In this respect, when the shock system is affected by power or breaking to the rear wheel, system efficiency and stability are compromised. Other systems use a quad-type configuration that only connects to a small section of the frame, providing less structural integrity.
Although recent motorcycle frames include a swing arm configuration, these configurations posses certain deficiencies which detract from their overall utility. The swing arm movement is typically in a pivoting motion upwardly and directed towards the front part of the motorcycle. This causes lateral instability for the rear wheel of the motorcycle. Many existing suspension systems provide inadequate control of wheel contact to the pavement. This can create safety concerns regarding the control of the increased stopping during breaking. Aside from the rear wheel wobbling, as described above, many current designs transfer force back to the front of the vehicle under acceleration.
Accordingly, there is a need for a rear suspension system for a two-wheeled vehicle which improves rear wheel geometry. Such a system should also increase lateral stability of the rear wheel of the vehicle and improve wheel contact with the pavement. Such a system should further contain the power under acceleration and not transfer force back to the front of the vehicle. The present invention fulfills these needs and provides other related advantages.
The present invention relates to a rear suspension system for two-wheeled vehicles. The system generally comprises first and second spaced apart and parallel support and axle plates, an upper arm assembly pivotally connected to a vehicle frame at a first end and to the support axle plates at the second end, and a lower arm assembly pivotally connected to the vehicle frame at a first end and the first and second support plates at a second end. First and second control arms are pivotally connected at their respective first ends to the vehicle frame, and at their respective second ends to the first and second support axle plates, or the lower arm assembly. The first and second support axle plates include aligned apertures which are configured to receive an axle of a rear wheel of the two-wheeled vehicle. A compressible shock unit is associated with the lower arm assembly, and connected at the opposite end thereof to the vehicle frame. The system has a generally triangular configuration.
The upper arm assembly is typically comprised of a base pivotally connected to the vehicle frame, and having a first elongated arm extending therefrom to a pivotal connection at the first support axle plate. A second elongated arm extends from the base generally parallel to the first arm to a pivotal connection point at the second support plate.
The lower arm assembly includes a base pivotally connected to the vehicle frame, and a first elongated arm extending from the base to a pivotal connection point at the first support axle plate. A second elongate arm extends from the base generally parallel to the first arm to a pivotal connection point at the second support axle plate.
The lower arm assembly includes a pivot arm assembly pivotally connected at a first end to the vehicle frame, and to the first and second arms of the lower arm assembly at the second end thereof. The pivot arm assembly comprises a pair of angular brackets spaced apart and parallel to one another. A shaft extends between first ends of the angular bracket for pivotal connection to the vehicle frame, and another shaft extends through second ends of the brackets for pivotal connection to the first and second arms of the lower arm assembly.
The shock unit is pivotally connected to the pivot arm assembly at one end, and pivotally connected to the vehicle frame generally opposite the pivot arm assembly.
With the system of the present invention, lateral stability is created for the rear wheel of the motorcycle.